A light emitting device using a light emitting diode chip (LED chip) is used as a backlight for a liquid crystal display device (LCD), an illumination device and the like. Particularly, since it becomes possible to realize a white light emitting device by combining a blue LED chip and a yellow phosphor, the device is rapidly put into use in respective fields. LCDs are applied to various displays of televisions, personal computers, mobile phones, car navigation systems and the like. In order to deal with environmental problems, also in an illumination device, switching from an incandescent lamp to a light emitting device using an LED chip is promoted.
When compared to conventional cold cathode tube and incandescent lamp, the light emitting device using the LED chip can realize energy saving, so that development thereof in the future is expected. Further, there is also a great expectation not only for energy saving but also for space saving, regarding the application of LED chip to the LCD and the illumination device. In order to deal with the space saving, namely, reduction in thickness and miniaturization, light emitting devices of surface-mount type and side-view type are developed. In either device, a light emitting diode chip is mounted on an accommodating container called a package, thereby realizing the space saving.
The surface-mount type is structured as a light emitting device in which an electrode and an LED chip are integrally formed on a substrate so that they can be directly connected to a mounting substrate. The side-view type is structured such that a light emitting direction is set to be horizontal with respect to a mounting face (for example, see JP-A 2006-229007 (KOKAI)). A package-shaped light emitting device is, as typified by the surface-mount type and the side-view type, a light source on which 1 to 2 pieces of LED chips are mounted, so that the device is provided with a reflecting member having a reflecting surface called a reflector in a package in order to enhance its light emission efficiency.
In order to increase a reflectance, mirror polishing has been conventionally performed on the reflecting member so that a surface roughness Ra becomes about 5 μm. However, although a regular reflectance is increased by a mirror surface, it is insufficient in terms of enhancement of light emission efficiency. A light emitting device in recent years using an LED chip reproduces various colors such as a white color by combining the LED chip and a phosphor layer. With the use only of the regular reflectance, a light from the LED chip does not uniformly reach the phosphor layer, so that there is a limit in the enhancement of the light emission efficiency, which is being clarified.